Cartesian diver



Oct. 10, 1950 F. c. MOGAUGHY CARTESIAN DIVER Filed Oct. 1, 1947 wvE/v roR FRANKLIN C Mc GHUGHY amen 4 48m ATTORNEYS dam/mu, {wax/n,

Patented Oct. '10, 1950 UNITED STATES PATENT OFFICE CARTESIAN DIVER Franklin -0. McGaughy, San Antonio, Tex. Application October 1, 1947, Serial No; 777,207

3 Claims. 1

.This invention relates to a toy and more particularly to a hydrostatic toy of the Cartesian diver type in which a diver descends in a body of liquid on application of pressure to the liquid.

The usual toy of the type herein described employs a figure floating in a body of liquid which, on the application of pressure, descends through the body of liquid. Divers heretofore available descend feet first on an increase in the pressure and rise head first when the pressure on the liquid is released. While the prior toys have been amusing and somewhat puzzling, it is desirable to provide a diver with a more realistic movement.

The Cartesian divers must have a gravity closely approximating that of the liquid in which they float in order to allow. them to act with small changes in the pressure on the liquid. Because of the small forces causing movement of the diver, the surface tension of the liquid is sulficient to interfere with satisfactory functioning of the toy. Divers hitherto available often come in contact with the walls ofthe container holding the liquid and tends to hang on the wall at the interface of the liquid with the air above it.

One of the attractions of the Cartesian diver as a toy is the more or less mystifying manner in which it operates. It is, therefore, desirable to provide a diver having as little visible apparatus as possible to make the operation of the diver more puzzling.

It is an object of this invention to provide a Cartesian diver which will descend and ascend in a realistic, lifelike manner as pressure on the liquid is varied.

Another object of this invention is to provide a Cartesian diver which will tend to center itself in the middle of a container of liquid so as to avoid hanging on the walls.

Still another object of this invention is to provide a toy having a minimum of mechanism visible to make the operation of the toy more puzzling.

A further object of this invention is to provide a trap to prevent spilling of liquid in case-part of the toy should break.

sian diver having concealed means for applyingpressure to the liquid and a diver that descends,

as well as ascends, in a headfirst manner.

In the drawings: Figure 1 is a vertical sectional view of a Carftesian diver built according to this invention showing the container for the liquid and the means for applying pressure to the liquid.

Figure 2 is an enlarged longitudinal sectional view of the diver 'of Figure 1. 1

Figure 3 is a modification of this inventio adapted for use as a display in a show window.

Referring to Figure l a Cartesian diver is illustrated in which a container l is filled with liquid to the level 2. A diver 3 floats in the liquid when, as illustrated in Figure l, the liquid is under substantially atmospheric pressure. The lower end of container l fits within a bowl 4 which serves as a support for the container, and also as a trap preventing spilling of the liquid under certainhaving its lower end open, but covered by a flexible elastic diaphragm 5. The upper end of the container is closed to allow pressure to be exerted on the liquid therein. Preferably, a fluid-tight cap 6 fits in the upper end of the container to allow access to the inside of the container.

The container I has a restricted neck I a short distance above its lower end which serves to center the diver as the toy is used and prevent its hanging against the wall. The diameter of neck I should ordinarily be small enough to prevent the diver 3 from passing through the neck when pressure is applied to the liquid. Neck! is substantially centrally located on the vertical axis of the container I whereby the diver descends to the neck as the pressure on the liquid is increased. When the pressure is released the diver rises essentially vertically to the center of the liquid surface.

In some forms of the invention neck 1 may have a diameter large enough to allow the diver 3 to pass therethrough. If the diver is allowed to pass through the neck, sufficient space must be provided below neck 1 to allow the diver to turn around and pass through the neck as it rises.

The lower end of container l is flanged at 8 to receive diaphragm 5. The diaphram 5 provides a flexible closure for the lower end of the container and thereby holds the liquid within the container. Diaphragm 5 is preferably made of rubber to allow it to stretch as the container is depressed. The diaphragm should fit tightly over the flange and preferably should be capable of holding the weight of the water within the vessel.

Container 1 may be partially or completely filled with any suitable liquid. If the container is completely filled, the diver is more sensitive to forces applied on the container subjecting the liquid to pressure. However, itis preferred that the liquid only fills the major portion of the container to allow the diver to come to the surface of the liquid and assume a lifelike swimming position. If an air space is left above the surface of the liquid, the air space should be relatively small to avoid the necessity of compressing a large volume of air before the liquid can be subjected to pressure.

Container I should be of a transparent material to allow the movement of the diver to be seen. It is preferred that the container be constructed of a plastic material having appreciable tensile strength to prevent breaking of the container when pressure is applied to the liquid since the toy will ordinarily be used by children.

The side walls 9 of bowl 4 in which container I is supported extend upwardly above the level of the flange Ii on the lower end of the container I to form a trap holding the liquid in container I if the diaphragm 5 should break. At the upper end of walls 9 a flange Ill extends inwardly over flange 8 of the container to limit the upward movement of the container. Inwardly extending flange I may consist of a number .of wings and slots, not shown, adapted to ;fit similar wings and slots on the flange of the container to provide a bayonet type connection permittingassembly of the toy.

In place of the bayonet type connection flange III may be one of the conventional split flanges which is removably connected to the walls 9 of the bowl 73.:

A projection I I extends upwardly from the bottom ofbowl 4 to engage the lower surface of diaphragm 5. The projection is ofany shape suitable to displace the diaphragm upwardly to compress the fluids Within the container. Surrounding the projection I I and engaging the bottom of the bowl 4 andthe lower surface of diaphragm where it contacts fiangeB ,is a compressed spring I2. Spring I2 provides support for the diaphragm and further prevents leaking of the liquid from the lower end of the container I. Spring I2 also urges the container upward to release the pressure when the force on the top of the container is released.

Details ofv construction of the diver are best illustrated in the sectional viewshown in Figure 2. The particular diver .there illustrated is in the form of ,a man, but, of course, the diver might be giventhe outward appearance of .a fish, submarine, etc. Diver .3 has a number ofv compartments 1 3 and Ill containingair and into whichthe liquid liquid such that the changes in efiective density resulting from the liquid entering and leaving the compartments I3 and I l-are sufficient to cause the diver to descend or ascend.

In order to avoid the artificial appearing movement of divers heretofore available, it is desired to make the diver 3 descend and ascend in a headfirst manner. Then when the pressure on the liquid is reduced, thediver should rotate to allow head end I? to lead as the diver rises. This effect is produced -by locatingand shaping compartments I3 and I l-to alter the position of the center of gravity of the diver as pressure is applied to the liquid.

Againreferring. tov Figure 2 compartments I3 and Marc located close to the head end I! of the diver. The effective density of the head. end I1 is thereby rendered variable and dependent upon the amount of liquid in compartments I3 and I4. Instead of compartments I3 and I4 a single compartment might be employed. The number of compartments will depend upon the shape of the diver and the manner in which it is desired that the diver rotate as pressure is applied to the liquid. The use of a number of compartments rather than a single compartment allows the added weight of the liquid to be applied to the diver at a number of different points along its length whereas a single compartment would tend to add the weight of the liquid entering the compartments at substantially a, single point. The location of compartments I3 and I l is such that the portion of the diver having a variable density is at the head end I'I. Compartments I3 and I4 are sufiiciently large and of the proper shape to make head end [I the heaviest end of the diver when compartments I3 and I4 contain substantial quantities of liquid and the lightest end when the compartments are relatively free of liquid. Diver 3 will, therefore, rotate about a horizontal axis when the pressure on the liquid is varied.

The density .of the foot end I8 of the diver is preferably low to tend to make the diver assume a substantially horizontal position when it comes to the surface of the, liquid. In the form of the invention shown in Figure 2 the effective density of the foot end of the diver is decreased by cavity i3. Cavity I9 is completely closed .to prevent liquid from entering the cavity as the pressure on the .liquid is increased. Rotation of the diver to allow the head end to lead as the diver moves is improved, however, if some liquid 20 is sealed in cavity I9.

.In order to prevent the diver from turning over on his back, which case conduits I5 and I6 would communicate with the .air above the liquid, the diver should be weighted along its front surface2 I to produce, in efliect, a keel.

To operatethe Cartesian diver assembled according to Figure 1 one merely presses on the top of the container Ito force it downward. The projection I I [onthe bottom of the bowl 4forces the diaphragm 5 into the open end of the container thereby subjectin the liquid within the container to pressure. The amount of pressure will be dependent upon the force with which the container is depressed and the volume of the air space above the liquid-level 2. The pressure within container I is communicated to the air within the compartments I3 and I4 of the diver 3 through conduits I5 and I6. As the air within thecompartmentsl3 and I4 is compressed, liquid flows through the conduits into the compartments to occupy the space made available. The water entering compartments I3 and I4 decreases the buoyant effect of the air in the compartments 0 sufficiently to cause the diver to sink. The diver will remain in the submerged position, as long as the force on the top of container I, and, consequently, the pressure on the liquid, is maintained. When the force on the top of the container I is removed, the container will rise and the deflection of the diaphragmiwill be ended" to release the pressure on the liquid. The air trapped in compartments I3 and I4 will expand and force the liquid from. theflcompartments, thereby decreasing .the..density of the .diver sufficientlyto cause. it to ascend. The. headend of the,.diver then becomes the lightest end and thediver rotates so that the head end willlead. as thediver ascends tow the surface of theliquid.

In the form of theinvention in which therelfi varying shapes.

a cavity I9 containing a liquid 20, the liquid will move towards the head end of the diver as the head end is depressed and the diver descends. The density of the extreme foot end of the diver is correspondingly decreased as the liquid moves towards the head end. Similarly, when the diver is submerged and the pressure on the liquid is released, the head end of the diver rises. The liquid 20 in cavity l9 then runs to the foot end of the cavity to move the center of gravity of the liquid nearer the foot end. It is apparent that the movement of the liquid will contribute to the change in location of the center. of gravity of the diver to encourage rotation and cause the diver to move in a headfirst manner.

Throughout the description of the invention, the terms head end and foot end have been used, These terms, of course, merely difierentiate the ends of the diver which may be of widely Similarly, the term air merely designates a gas that is insoluble in the liquid.

A modification of the invention suitabl for use as a display in a show window is illustrated in Figure 3. In this form of the invention a container 22 is provided to retain the liquid which fills container 22 to the level 23. is closed both at top and bottom.

Extending into the air space above the liquid level 23 is a conduit 24. Conduit 24 is connected with a bellows 25 which is alternately compressed and extended by a connecting rod 26. An electric motor 27 drives a speed reducing worm gear 28 to which a crank arm 29 is connected. A linkage member 30 connects crank arm 29 and connecting rod 26 to impart reciprocating motion to the connecting rod. When the invention is used as a display, the mechanism compressing the bellows should be concealed.

Located within the compartment 22 is a diver 3|. Diver 3! should be constructed similarly to diver 3 in order that it will rotate as the pressure changes. In the form of the invention shown in which the diver 3| is a submarine, substantially horizontal fins 32 may be provided to cause the diver to move horizontally as well as vertically as it ascends or descends. It may be necessary to curve fins 32 slightly to obtain the desired movement.

The operation of the form of the invention shown in Figure 3 is believed to be clear. motion produced by motor 27 is transferred through the speed reducinggear to the crank arm 29 which, through suitablelinkage, causes movement of the connecting rod 26. Connecting rod 26 compresses bellows 25 forcing the air from the bellows into the air space above the liquid in the container 22. It is not necessary that the bellows operate on air. Bellows 25 may communicate with the liquid and subject it to pressure directly.

As the pressure on container 22 is increased, the compartments, not shown, in diver 3| are partially filled with liquid and the diver descends. As rotation of crank arm 28 continues the bellows 25 will be drawn into an extended position and the pressure on the liquid will be reduced. The diver will then ascend to the surface of the liquid.

A Cartesian diver constructed according to this Container 22 The invention moves in a realistic, lifelike manner. The means for applying pressure to the liquid are so arranged that it is not obvious, as it has been in toys heretofore available, that pressure is being applied to the liquid. The concealed manner of operating and the headfirst motion of the diver greatly increase the entertainment and bewilderment derived from the toy.

The present invention has been described in detail herein for purposes of illustration. One skilled in the art may depart from those details without deviating from the concept of this invention, the scope of which is-defined by the appended claims.

I claim:

A Cartesian diver comprising a container having a liquid therein, means for subjecting the liquid to pressure, a diver in the container, said diver having a center of gravity causing it to lie substantially horizontally at the surface of the liquid when the liquid is subjected to a low pressure, a compartment in the diver between the center of gravity and one end of the diver, said compartment containing air and having a conduit to admit liquid to the compartment when the pressure is increased thereby changing the center of gravity of the diver and causing it to rotate about a horizontal axis when the pressure on the liquid is changed, the flow of water into and from the compartment causing the diver to descend when the pressure is increased and ascend as the pressure is decreased.

2. A Cartesian diver comprising a container for a liquid, means for subjecting the liquid to pressure, a diver in the container having a compartment containing air atthe head end, a conduit allowing liquid to compress the air and enter the compartment as the pressure on the liquid is increased, the foot end being of a density substantially equal to the density of the liquid between high and low pressures whereby the foot end will be suspended ,higher than the head end when the pressure is high and lower when the pressure is low.

3. A Cartesian diver comprising a container for a liquid, means for subjecting the liquid to ressure, a diver in the container having a comp-artment containing air at the head end, a conduit allowing liquid to enter the compartment, a compartment in the portion of the diver remote from the head end containing liquid and air and being closed to the main body of liquid whereby the center of gravity of the diver is near the head end when the liquid is at high pressure and liquid flows into the compartment and near the other end when the liquid is at low pressure.

FRANKLIN C. MCGAUGHY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,107,481 Boggs Aug. 18, 1914 1,454,426 Clements May 8, 1923 1,675,522 Weidinger July 3, 1928 

